Diaphragm actuated valve



May 3E, 1932. c. A. CAMPBELL DIAPHRAGM ACTUATED VALVE Filed May 3, 1928alli! I nl v/f. il

Patented May 3l, 1932- UNITED -STATES PATENT ol-jFlcE CHAllIlS CAMPBELL,F WATERTOWN, NEW YORK, ASSIGNOR TO THE NEW YORK AIR BRAKE COMPANY, ACORPORATION F NEW JERSEY DIAPRAGM ACTUATED VALVE Application tiled May31928. Serial No. 274,950.

This invention relates to diaphragm actuated valves, and will bedisclosedg as applied to a so-called governor top foi` use with pumpgovernors of air brake systems.

Valves of this general character have been used in other combinations inthe air brake art, and essentially similar valves are used in otherarts. For example, they have been used as so-called terminal checkvalves for preventing flow of steam from a steam passage in a locomotiveto a force feed lubricator connected to feed oil to said steam passage.

- Consequently, the invention hereinafter disclosed is intended forgeneral application, although its utility will be discussed primarilyfrom the standpoint of the air brake art.

In such valves as ordinarily constructed the pin valve carried by thediaphragm coacts with a relatively small port in a seat bushing which ispressed to place. The valve and seat are subject to deformation, usuallyas the result of scale which becomes embedded in the seat. To minimizethe presence of rust and scale, the valve bodies of governor tops havecommonly been made of brass.

One purpose of the present invention is to permit the body to be made ofcast iron, or other relatively inexpensive material, without sacrificeof efficiency.

Another object of the'invention is to make `the valve seat readilyremovable so that the housing of the pin valve mechanism need never bedismounted to replace the seat.

Another object of the invention is to permit the diaphragm with itscomplete mount, including the valve and seat, to be assembled, shippedand "replaced as a unit, facilitating replacement of parts andeconomizing in the cost of repairs.v

The features of the invention are illustrated in the accompanyingldrawings, in which,-

Fig. 1 is a vertical yaxial section of the preferred embodiment of theinvention.

Fig. 2 is a perspective view of the replacement unit, consisting of thediaphragm, diaphragm mount, pin valve, and seat, held in assembledrelation by a clip.

Fig. 3 is a perspective View of the clip beforeapplication to theassembled unit.

Referring first to Fig. 1, 6 represents the `valve body or housing. Thismay be made of cast iron instead of brass, as has been the priorpractice. It is provided at its lower end with a threaded nipple 7, bymeans of which it is screwed into the pump governor structure. Thenipple 7 is formed with the usual port 8. The port 8 forms acommunication by which air pressure is admitted to the piston chamber ofthe usual governor mechanism, as will be well understood. The union 9offers connection to a pipe leading to the reservoir in which the pumpgovernor acts and is there internally threaded to receive the combinedspring boX and diaphragm clamping nut 13. A circular cup-like member 14is mounted within the housing upon a flange 15. This member 14 serves asa combined diaphragm support and valve seat, and is readily removable.To secure .ready removal the member 14 is centered by means of a closeslip fit at 16, there being peripheral clearance at 17 so that if themember 14 be lifted a short distance it will be entirely free. At itslower end the member 14 is formed with a ported nipple 18 which extendsinto a countersink in the housing 6. This countersink communicatesdirectly with the passage 8.

Above the nipple 18 is a shoulder 19 which enters a larger and shallowercountersink in the body 6 and there seats upon and seals against agasket 21. The upper margin of the member 14 is beveled inwardly, asshown at 22, and thus serves as a seat for the periphery of the flexiblemetallic diaphragm 23. overlying this diaphragm is an inwardly beveledclamping ring 24. This ring is preferablv beveled both at the top andbottom so as to be reversible.

The pin valve seat is formed in member 14, as indicated at 25, and thepin valve coacting with seat is shown at 26. The pin valve is slidablymounted in a mit 27. This passes through a hole at the center of thediaphragm ing member w ichassures accurate seatingA of the pin valve 26on its seat 25.

The pin valve is constructed in the usual manner, that is, it has anenlarged head 32 which is urged upward by a coil spring 33 surroundingthe stem portion of the valve. Preure iiuid entering the body 6 by wayof the passage 11, flows first beneath the cup' shaped member 14 andthen through a passage 34 formed through the member 14, to the spacebeneath the member 14 and the lower face of the diaphragm 23. Thepassage 34 is vpreferablydocated onthe side remote from the passage 11,'though this is not strictly necessary. The eiect is to isolate, in aneiective degree, the pin valve 26 and its seat 25, from the interiorwall of the housing 6.. Thus rust and scale are dropped in the chamber12 be neath the member.14, and even though the housing 6 be of castiron, or ether corrodible metal, no serious trouble from scale is en- Pcountered. With the conventional pin valve structure the use of a castiron body has been demonstrated to be unsatisfactory.

Threaded into the upper end of the memf ber 13 is an adjustable springseat 35, which,

as usual, is locked in place by a combined cap and check nut 36 threadedon to the member 35 and entering into thrust enga ement with the member13. A loading spring 37 reacts upward against themember 35 and down'-vward against a bearer member 38 which has a conical pin 39 seated in aconical recess formed in the upper portion of the member 29 to receiveit.` This conical recess has a somewhat wider angle so as to permit atleast moderate universal angular motion of' the member 39.

In prior structures, if the pin valve seat became damaged, it wasnecessary to remove the'entire governor top. This was for the reasonthat the pin valve seat was pressed to place and could not besatisfactorily replaced or refinished otherwise. In the presentconstruction this diliiculty is not encountered.

To vmake va repair, cap 36, spring seat 35, andv the sprin 37, areremoved.4 Then the spring box mem r 13 is removed, whereupon it becomespossible to lift out the clamping ring 24, the diaphragm 23 with theattached valve,

and the combined diaphragm support and lpin valve seat 14. These unitsare made on an interchangeable basis and may be indireplaced, but it ispreferred, inv order to secure absolutely perfect centering of the pinvalve relatively to its seat, to replace all the units above mentionedby a set of units properly coordinated with each other and tested at thefactory for accuracy. This is accomplished by assembling these units bymeans of a clip which remains upon the units until they are to beinserted into the housing 6.

This clip is best shown in Figs. 2 and 3, and consists of a'metallicannulus 41 having a plurality of bendable fingers 42 which extendperpendicularl to the plane of the annularmember 41 o the clip. Theannular portion 41 surrounds the upward extending boss 29 of the thrustmember and overlies this member and the clamping ring 24. The extremeends lof the fingers 42 are bent in, as

shown in Fig. 2, and as indicated in dotted lines at 43 in Fig.-3 toengage the seating rim of the member 14. The clip holds a carefullffitted set of replaceable elements inI assem led relation in thehousing 6. The damaged parts, which have been removed, are returned tothe facto to be reconditioned.

It willbe observe that this reconditioning does not affect the ousidedimensions of the assembled unit, shown. in Fig. 3.

uently, while strict interchangeability of t e complete unit ismaintained, each valve may be reconditioned with reference to itsarticular seat without maintaining strict interchangeability of thevalves perse. The effect is to secure the economy in reconditioningmaterial that is secured at present, Without requiring dismounting ofthe entire gov- 'ernor top, and without requiring the breaking of anyipejoints.

What is c aimed is,-

In a device of the class described, the combination of a body having aninlet passage, a discharge passage, and an annular shoulder above .saidpassages; a gasket surrounding said discharge passage; a combined valveseat and diaphragm sup rt sustained on said shoulder in sealing re ationwith said gasket, 4there being a ported valve seat in the upper face ofthe su port leading to the discharge port in the bo and another passagein said sup ort through'which fluid may ass from the inlet port tothespace above sai support; a diaphragm mounted on said supporta valvearran to be actuated by said diaphragm an to coact with said seat;releasable means for clamping said diaphragm Conse-

